Commutator-brush for electric motors and dynamos



(NOMOdeL) T. A. EDISON.

OOMMUTATOR BRUSH FOR ELECTRIC MOTORS AND DYNA-MOS. No. 468,950. PatentedFeb. 16, 1892.

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THOMAS A. EDISON, OF LLEWELLYN PARK, NEW JERSEY.

COMMUTATOR-BRUSH FOR ELECTRIC MOTORS AND DYNAMOS.

SPECIFICATION forming part of Letters Patent No. 468,950, dated February16, 1892.

Application filed April 4, 1891. Serial No. 387,693- (No model.)

v a specification.

In my patent, No. 276,233, dated April 24, 1883, are set forth theadvantages of the use of current-collectors forming bridges of highresistance between the bars of the commutator-cylinder of adynamo-electric machine or electro-dynamic motor, whereby the spark atthe commutator-bars, due to the breaking of local circuits, isprevented, and in said patent is described the use for this purpose ofcurrent-collectors of inferior conducting capacity, making inferiorcontact at the surface of the commutator-cylinder.

In my patent, No. 298,954, dated May 20, 1884, is set forth a modifiedarrangement in which the high-resistance bridge between thecommutator-segments is formed by resistanceconductors external to thebrush.

The present improvement relates to a different arrangement of theresistances and current-collectors of the same general character as thatlast mentioned.

Figure 1 of the drawings illustrating the improvement shows an end viewof a commutator-cylinder with one commutator-brush resting thereon, thesecond brush not being shown, the holder being partially in sect-ion.Fig. 2 is a plan View of the brush-holder and brushes, the springs beingomitted.

1 is a commutator-cylinder having around it several conducting-segments2 and insulating-segments 3, the conducting and insulating segmentsbeing of about the same width. Above the cylinder is a brush-holder 4,preferably of porcelain and held adjacent to the cylinder in anysuitable manner, in which are supported several current-collectors 5,having a thickness of about equal to one-half the width of a segment.Four of these collectors are shown, and they are in the form ofrectangular bloeks or plates and are separated from each other byinsulation 6, the collectors being so mounted that they can move up anddown independently, but cannot turn in their sockets. Pressing on theend of each col-= lector is a spring '7, each spring being connected bya wire 8 to a resistance 9.

10 is a wire leading from the resistancewires to the current supply whenthe commutator is used on a motor, or to the circuit to be supplied withcurrent when it is used on a dynamo. mutator, which is not shown, may belike the brush described. The several sections of the current-collectingdevice or brush being independently movable, will always bear on thesurface of the cylinder and make good contact therewith, and theresistance-conductors will be thrown into circuit in such manner as toreduce the spark, when by passing from one segment to another a localcircuit is formed, since the current in the local circuit will have topass through one or more of the resistanceconductors in one directionand then through others of said conductors in the opposite direction.

Having thus described the invention, what I claim is '1. Thecombination, with a commutatorcylinder, of a commutator-brush havingseveral current collecting devices, each independently movable in adirection toward and from the commutator-cylinder, and a resistanceconnected to each collecting device, substantially as described.

2. The combination, with a commutatorcylinder, of severalcurrent-collecting devices insulated from each other and independentlymovable, a spring bearing on the end of each collector, and a resistanceconnected to each of 'said collecting devices, substantially asdescribed.

3. The combination, with a commutatorcylinder in which the insulatingand conductin g segments are of substantially equal size, of severalcurrent-collectors about half as thick as thecommutator-segments,separated from each other, and a resistance connected to each collector,substantially as described.

4. The combination, with a commutatorcylinder, of a brush-holder,several currentcollecting devices or brushes supported therein, butseparated from each other by insulating material, and resistancesconnected to the brushes, substantially as described.

5. The combination, with a commutatorcylinder, of a brush holder ofinsulating ma- The second brush of the comterial, such as porcelain,several current-colmovable toward and from the commutator lecting blockssupported therein and indecylinder, substantially as described. 10pendently movable, and a spring pressing on This specification signedand witnessed each brush, substantially as described. this 20th day ofMarch, 1891.

5 6. The combination of a brush-holder and THOS. A. EDISON.

several rectangular current-collecting blocks Witnesses: supported insaid holder, said blocks being, l-I. WV. SEELY,

insulated from each other and independently RICHD. N. DYER.

